Dissertations / Theses on the topic 'Frequency STORM'

Thesis (M.S. in Physical Oceanography) Naval Postgraduate School, December 1996.
Thesis advisor(s): Robert H. Bourke, James H. Wilson. "December 1996." Includes bibliographical references (p. 131-132). Also available online.

Elevated nutrient concentrations present significant challenges to surface water quality management globally, and dissolved organic matter mediates several key biogeochemical processes. Storm events often dominate riverine loads of nitrate, phosphorus, and dissolved organic matter, and are expected to increase in frequency and intensity in many regions due to climate change. The recent development of in situ optical sensors has revolutionized water quality monitoring and has highlighted the important role storms play in water quality. This dissertation focuses on improving the application of in situ optical water quality sensors and interpreting the high-frequency data they produce to better understand biogeochemical and watershed processes that are critical for resource management. We deployed in situ sensors to monitor water quality in three watersheds with contrasting land use / land cover, including agricultural, urban, and forested landscapes. The sensors measured absorbance of ultraviolet-visible light through the water column at 2.5 nanometer wavelength increments at 15-minute intervals for three years. These deployments provided a testbed to evaluate the sensors and improve models to predict concentrations of nitrate, three phosphorus fractions, and dissolved organic carbon using absorbance spectra and laboratory analyses through multivariate statistical techniques. In addition, an improved hysteresis calculation method was used to determine short-timescale storm dynamics for several parameters during 220 storm events. Goals of each dissertation chapter were to: (1) examine the influences of seasonality, storm size, and dominant land use / land cover on storm dissolved organic carbon and nitrate hysteresis and loads; (2) evaluate the utility of the sensors to determine total, dissolved, and soluble reactive phosphorus concentrations in streams draining different land use / land covers, and perform the first statistically robust validation technique applied to optical water quality sensor calibration models; and (3) analyze storm event dissolved organic matter quantity and character dynamics by calculating hysteresis indices for DOC concentration and spectral slope ratio, and develop a novel analytical framework that leverages these high frequency measurements to infer biogeochemical and watershed processes. Each chapter includes key lessons and future recommendations for using in situ optical sensors to monitor water quality.

The United States Weather Bureau had published Technical Paper No. 40 (TP-40) in 1961 which provides a rainfall atlas for the United States. These rainfall frequencies have been used by engineers throughout the United States including Jefferson Parish, Louisiana. Rainfall from Audubon and the New Orleans International Airport rain gauge stations were used with the Log Pearson Method to provide rainfall frequency for Jefferson Parish, Louisiana. The results from the frequency rainfall that were developed for this research along with the current Jefferson Parish design storm rainfall were applied to a typical urban development to evaluate the extent of flooding.

Storms can be both destructive and valuable at the same time. They expose coastal areas to various risks but can also enhance the supply of wind energy and provide marine ecosystems with oxygen rich water. As the North Atlantic Oscillation (NAO) is known to have a significant impact on the wind climate in Europe, investigating its interconnection to storm frequency and intensity under global warming circumstances in the Northern Baltic Sea region was of interest in this study. Wind speed data series of annual storm counts were obtained from five meteorological stations along with PC-based NAO values over the period 1960-2017. The data series were analysed in Microsoft Excel and modelled using a Poisson regression or negative binomial regression model in SPSS Statistics. The results display an unsystematic spatial pattern both in the association to the NAO as well as in the overall storm frequency. However, storm (≥ 21 m s-1) frequency has generally been decreasing, whereas the proportion of severe storms (≥ 24 m s-1) has slightly been increasing, suggesting a tendency toward stronger but fewer storms. Even though only certain data series display statistically significant findings (p ≤ .05), a majority of the winter storms and severe winter storms display a positive association, indicating that a higher NAOI is related to a greater number of winter storms. The spatial and temporal variability in the obtained results can partially be explained by storm tracks and prevalent wind directions. Nevertheless, inhomogeneities do presumably affect the wind speed observations through internal and external influences and changes related to the meteorological stations. Future research should, therefore, also consider integrating other storm related parameters, such as direct air pressure measurements, wave heights and storm surges, as well as implement different data homogenization methods and techniques.

As the globe continues to warm, coastal communities across the world will increasingly be faced with rising sea levels, as well as changes in storm surge frequency and magnitude. Significantly, most infrastructure, settlements and facilities are located near the coast. While coastal communities have benefitted from the many advantages of living and working in these areas, inevitably they also face the threat of natural disasters. With concern for the consequences of sea level rise (SLR) and associated storm surge (SS), the primary, and most urgent topics for decision makers are the assessment of vulnerability and the evaluation of adaptation measures. However, due to uncertainty in climate change predictions, many vulnerability and adaptation assessments and most town planning activities, which are based on an the assumption that the sea level will remain stable in the future, are in a state of flux. Added to the dilemma is the realisation that the impacts of SLR will, most likely, be spatially non-uniform across the world. It is therefore essential for decision-makers to consider the dynamic and spatial characteristics of these changes in assessing the impacts of SLR when making decisions about future infrastructure and community life.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
Science, Environment, Engineering and Technology
Full Text

Extreme rainfall statistics are important for the design and management of the water resource infrastructure. The standard approach for extreme rainfall event severity assessment is the Intensity-Duration-Frequency (IDF) method. However, this approach does not consider the spatial context of rainfall and consequently does not properly describe rainfall storm severity, nor rarity. This study provides a critical account of the current standard practice and presents an approach that takes into consideration both the spatial context of rainfall storms, and indirectly incorporates runoff to produce a representative approach to assessing urban rainfall storm severity in terms of flood potential. A stepwise regression analysis was performed on a dataset of individual rainfall storm characteristics to best represent documented basement floodings in the City of Edmonton. Finally, the urban rainfall storm flood severity index was shown to be most representative of the documented basement floodings' severity when compared to that of the IDF method.

Recent events such as the New Orleans floods and the Japanese tsunami of 2011 have highlighted the uncertainty in the quantification of the magnitude of natural hazards. The research undertaken here has focussed on the uncertainty in evaluating storm surge magnitudes based on a range of statistical techniques including the Generalised Extreme Value distribution, Joint Probability and Monte Carlo simulations. To support the evaluation of storm surge frequency magnitude relationships a unique hard copy observed sea level data set, recording hourly observations, was acquired and digitised for Devonport, Plymouth, creating a 40 year data set. In conjunction with Devonport data, Newlyn (1915-2012) tide gauge records were analysed, creating a data set of 2 million data points. The different statistical techniques analysed led to an uncertainty range of 0.4 m for a 1 in 250 year storm surge event, and 0.7 m for a 1 in 1000 storm surge event. This compares to a 0.5 m uncertainty range between the low and high prediction for sea level rise by 2100. The Geographical Information system modelling of the uncertainty indicated that for a 1 in 1000 year event the level uncertainty (0.7 m) led to an increase of 100% of buildings and 50% of total land affect. Within the study area of south-west England there are several critical structures including a nuclear licensed site. Incorporating the uncertainty in storm surge and wave height predictions indicated that the site would be potentially affected today with the combination of a 1 in 1000 year storm surge event coincident with a 1 in 1000 wave. In addition to the evaluation of frequency magnitude relations this study has identified several trends in the data set. Over the data period sea level rise is modelled as an exponential growth (0.0001mm/yr2), indicating the modelled sea level rise of 1.9 mm/yr and 2.2 mm/yr for Newlyn and Devonport, will potentially increase over the next century by a minimum of 0.2 m by 2100.The increase in storm frequency identified as part of this analysis has been equated to the rise in sea level, rather than an increase in the severity of storms, with decadal variations in the observed frequency, potentially linked to the North Atlantic Oscillation. The identification as part of this study of a significant uncertainty in the evaluation of storm surge frequency magnitude relationships has global significance in the evaluation of natural hazards. Guidance on the evaluation of external hazards currently does not adequately consider the effect of uncertainty; an uncertainty of 0.7 m identified within this study could potentially affect in the region of 500 million people worldwide living close to the coast.

Large-scale atmospheric disturbances play important roles in determining the general circulation of the atmosphere during the North Pacific boreal winter. A number of scientific questions have been raised due to these disturbances’ spatial and temporal complexity as well as the hydrological implication associated with them. In this dissertation, the principal goal is to further improve our understanding of the atmospheric high frequency (HF) and intermediate frequency (IF) disturbances active over the North Pacific. The study focuses on their energetics, intraseasonal and interannual variability, and the resulting hydrological impact over the eastern North Pacific and Western U.S. including extreme events. To delineate the characteristics of HF and IF disturbances in the troposphere, we first derive a new set of equations governing the local eddy kinetic energy (EKE), and assess the critical processes maintaining local budgets of the HF and IF EKE. The diagnosis assesses the 3-D patterns of energy flux convergence (EFC), barotropic conversion (BT), baroclinic conversion (BC), and cross-frequency eddy-eddy interaction (CFEI). The local EKE budget analysis is followed by an investigation of the modulation of HF and IF eddy activity by different modes of low frequency climate variability. On interannual timescales, the response of various local energetic processes to El Niño-Southern Oscillation (ENSO) determines the HF and IF EKE anomalies and the role of CFEI process is important in producing these anomalies. Also on interannual timescales, winter precipitation deficits associated with suppressed cyclonic activity, i.e., negative HF EKE anomalies, are linked to severe droughts over the U.S. Southern Great Plain (SGP) region. The suppressed cyclonic activity is, in turn, tied to phase changes in the West Pacific (WP) teleconnection pattern. On intraseasonal timescales, variations in HF disturbances (a.k.a. storm tracks) over the North Pacific are closely coupled with tropical convection anomalies induced by the Madden-Julian Oscillation (MJO), and partly drive larger scale intraseasonal flow anomalies in this region through eddy-eddy interactions. Anomalous HF eddy activity induces subseasonal transitions between “wet” and “dry” regimes over the west coast of North America. Also on intraseasonal timescales, the East Asian cold surge (EACS) is found to provide a remote forcing of the winter precipitation anomalies in the western U.S. This modulation is achieved through “atmospheric rivers” (ARs), which are narrow channels of concentrated moisture transport in the atmosphere and are responsible for over 70% of the extreme precipitation events in the western U.S.. EACS effectively modulates the IF disturbance activity over the North Pacific, and the anomalous IF disturbances lead to the formation of an AR over the eastern North Pacific that ultimately induces precipitation anomalies in the western U.S. Analyses of the simulations from the NCAR Community Climate System Model version 4 (CCSM4) demonstrate that the connections among the EACS, AR and western U.S. precipitation are better captured by a model with higher spatial resolutions. The improved simulation of these connections is achieved mainly through a better representation of the IF disturbances, and the associated scale-interaction processes in the higher resolution model.

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV
This paper describes the methodology and the results of the interferences analysis that the JASON3 spacecraft has to deal with, as part of the PROTEUS platform series, sharing frequencies, modulation schemes and ground network.

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2005.
Includes bibliographical references (leaves 67-68).
Currently, no adequate method exists for determining how frequently a retail store in a supermarket chain should receive deliveries from its distribution center. Existing methods neglect many crucial constraints, such as the necessity for deliveries to fall on fixed days of the week, severely limited shelf space, and the inability for many stores to hold additional overstock product in a backroom. This paper addresses the problem by outlining a new method for determining the delivery frequency by developing a simulation model for the replenishment process of a supermarket chain. The model can also be used to provide insight into other aspects of the replenishment process, such as shelf space allocation, and reorder rules. Using this model, we were able to show that significant cost savings were available to the supermarket chain we worked with on the project by changing the delivery schedules for their stores.
by Christopher Wayne Kerslake.
M.Eng.in Logistics

Tall slender buildings are easily set in motion by wind and earthquakes but by estimating the buildings horizontal natural frequencies in the design phase, these motions can be kept within acceptable boundaries. There are many parameters that decides the natural frequency of a building and it can therefore be difficult to calculate it. There are a few ways though to estimate horizontal natural frequencies of tall buildings and two methods have been tested in this report. Both methods give the frequency of a clamped-free cantilever but one of them requires a single degree of freedom system whilst the other handles a multi degree of freedom system. The methods are called SDOF method and MDOF method in this report. A fictional building was created for this project to be the reference object in the comparison between the two methods SDOF and MDOF. The walls and floors of the building was designed with the support of both an acoustic engineer and a structural engineer to create a realistic building. A building’s natural frequency is dependent of the self-weight, stiffness and height of the building and it was therefore important to design these components with care. The fictional building is called House 1 and is a 10 story, almost square building about 20 m wide and broad and 30 m high. This report does not only compare the natural frequencies obtained from the two different calculation methods, but it also shows the difference in frequency in timber and concrete structures. Shear walls constitutes the horizontal stabilization system of the fictional building and both a CLT core and a concrete core is designed and compared. It is only the walls that comes in two different versions, the floorings consist of CLT boards for both structures tested. The horizontal natural frequencies of House 1 were about 2 Hz and 3 Hz for the CLT version and concrete version respectively. It was expected to get frequencies within that range considering the height of House 1. The CLT core having a lower frequency than the concrete core was also expected since concrete is a stiffer material than wood. To be able to make a fair comparison between the SDOF method and the MDOF method, House 1 was designed with the same dimensions and stiffness on all floors because the SDOF method requires that. The results from the two methods are almost identical with only 0.3 Hz and 0.4 Hz difference for the concrete and CLT respectively. For a shear wall structure with a consistent stiffness, weight and dimension, any of the two methods can be used to estimate the horizontal natural frequency. However, it is not realistic for a building of 30 m or higher, to have the same dimensions on the load bearing structure on all floors which makes the MDOF method more accurate in more cases than the SDOF method.
Höga slanka byggnader kan sättas i svajande rörelser av vind och jordbävningar, men genom att uppskatta byggnadernas horisontella egenfrekvenser i den tidiga konstruktionsfasen kan dessa rörelser hållas inom acceptabla gränser. Det är många parametrar som bestämmer byggnadens egenfrekvens och det kan därför vara svårt att beräkna den. Det finns dock några sätt att uppskatta horisontella egenfrekvenser hos höga byggnader och två metoder har testats i denna rapport. Båda metoderna ger frekvensen av en fast inspänd konsolbalk men en av dem kräver ett enfrihetsgradsystem medan den andra kan hantera ett system med flera frihetsgrader. Metoderna kallas SDOF-metoden och MDOF-metoden i denna rapport. En fiktiv byggnad skapades i detta projekt för att vara referensobjekt i jämförelsen mellan de två metoderna SDOF och MDOF. Byggnadens väggar och golv konstruerades med stöd av både en akustiker och en konstruktör för att skapa en realistisk byggnad. Byggnadens egenfrekvens är beroende av byggnadens egenvikt, styvhet och höjd och det var därför viktigt att utforma dessa komponenter med omsorg. Den fiktiva byggnaden kallas House 1 och är en 10 vånings-, nästan fyrkantig byggnad ca 20 m lång och bred och 30 m hög. Denna rapport jämför inte bara egenfrekvenserna erhållna från de två olika beräkningsmetoderna, den visar även skillnaden i frekvens i trä- och betongkonstruktioner. Skjuvväggar utgör det horisontella stabiliseringssystemet för den fiktiva byggnaden och både en KL-kärna och en betongkärna har utformats och jämförts. Det är bara väggarna som skiljer de två olika versionerna åt, bjälklagen består av KL-skivor i båda fallen. De horisontella egenfrekvenserna hos House 1 var ca 2 Hz och 3 Hz för KL-version respektive betongversion. Frekvenser inom detta område var väntade med tanke på höjden av House 1. Att KL-kärnan skulle ha en lägre frekvens än betongkärnan förväntades också eftersom betong är ett styvare material än trä. För att kunna göra en rättvis jämförelse mellan SDOF-metoden och MDOF-metoden, var House 1 utformad med samma dimension och styvhet på alla våningsplan eftersom SDOF-metoden kräver det. Resultaten från de två metoderna är nästan identiska med endast 0,3 Hz och 0,4 Hz skillnad för betong respektive KL. För en skjuvväggskonstruktion med en kontinuerlig styvhet, vikt och dimension kan båda de två metoderna användas för att uppskatta den horisontella egenfrekvensen. Det är dock inte realistiskt för en byggnad på 30 m eller högre att ha samma dimensioner på den lastbärande konstruktionen på alla våningar vilket gör MDOF-metoden mer korrekt i fler fall än SDOF-metoden.

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California
Modern spectrally efficient telemetry transmitters are beginning to find their way on a variety of airborne test platforms. Many of these platforms also include Global Positioning System (GPS)-based Time-Space-Position-Information (TSPI) instrumentation systems. Due to space and other limitations, many of these platforms have demanding antenna placement limitations requiring closely spaced antennas. This paper describes steps taken to identify and mitigate potential interference to GPS-based TSPI instrumentation systems by these new technology transmitters. Equipment characterization was accomplished to determine interference potential of the proposed new transmitters and susceptibility of several GPS TSPI receivers. Several filtering techniques were identified as possible solutions to the anticipated interference problems. Telemetry (TM)/GPS system mockups and laboratory tests of the same were accomplished. Open-air testing was then accomplished to validate laboratory results. Finally, on aircraft tests were accomplished prior to performing any aircraft system modifications. Results of these test efforts are presented for others to consider when planning similar modifications to other platforms.

During the last decades, it has been brought to light that well organized logistics processes have contributed to competitive advantages for companies. Mio AB, a chain store warehouse and the second largest furniture company in Sweden, is operating in the middle of an expansion phase with growing revenue. As a consequence, larger volumes of goods are handled, space utilization become more scarce and the everyday operations within the internal logistics are affected. Therefore, the processes within the warehouse department were measured by performing a frequency study, registering how time was distributed between the different work tasks. In order to fully understand the processes, interviews were held with management and personnel. After analyzing previous research that could help guide to ease the impositions and analyzing the result of the frequency study, wastes were identified and new ways of working were suggested. The result firstly presents how to organize internal logistics operations in chain store warehouses to gain competitive advantage. Secondly, keeping in mind that firefighting stressed situations usually is not sustainable and only eases loads temporarily, long-term sustainability and ethics were addressed. Concluding that in order to optimize internal logistics operations in chain store warehouses and gain a long-term competitive advantage in a sustainable way, are achieved through standardizing work tasks, ensuring commitment of management and personnel and applying systems to serve the people and processes. Lastly it is advised to keep in mind the impact a company have on its surroundings and the importance of engaging in sustainable and ethically friendly operations, in order to achieve long-term competitive logistics.

RFID technologies are being recently adopted in the retail space tracking consumer in-store movements. The RFID-collected data are location sensitive and constantly updated as a consumer moves inside a store. By capturing the entire shopping process including the movement path rather than analyzing merely the shopping basket at check-out, the RFID-collected data provide unique and exciting opportunities to study consumer purchase behavior and thus lead to actionable marketing applications.This dissertation research focuses on (a) advancing the representation and management of the RFID-collected shopping path data; (b) analyzing, modeling and predicting customer shopping activities with a spatial pattern discovery approach and a dynamic probabilistic modeling based methodology to enable advanced spatial business intelligence. The spatial pattern discovery approach identifies similar consumers based on a similarity metric between consumer shopping paths. The direct applications of this approach include a novel consumer segmentation methodology and an in-store real-time product recommendation algorithm. A hierarchical decision-theoretic model based on dynamic Bayesian networks (DBN) is developed to model consumer in-store shopping activities. This model can be used to predict a shopper's purchase goal in real time, infer her shopping actions, and estimate the exact product she is viewing at a time. We develop an approximate inference algorithm based on particle filters and a learning procedure based on the Expectation-Maximization (EM) algorithm to perform filtering and prediction for the network model. The developed models are tested on a real RFID-collected shopping trip dataset with promising results in terms of prediction accuracies of consumer purchase interests.This dissertation contributes to the marketing and information systems literature in several areas. First, it provides empirical insights about the correlation between spatial movement patterns and consumer purchase interests. Such correlation is demonstrated with in-store shopping data, but can be generalized to other marketing contexts such as store visit decisions by consumers and location and category management decisions by a retailer. Second, our study shows the possibility of utilizing consumer in-store movement to predict consumer purchase. The predictive models we developed have the potential to become the base of an intelligent shopping environment where store managers customize marketing efforts to provide location-aware recommendations to consumers as they travel through the store.

In a school for children from 6-9 years in a small town in the southeast of Sweden, is areading activity program in progress since 8 years. The original purpose of this program wasto enhance the student’s reading interest. All of the students read at least one book a week andthen they review the book in front of the class.

The purpose of the present study was to examine vocabulary, word retrieving, narrative skillsand grammatical abilities in children in this school. The objectives were to investigate if thechosen language abilities in these children were different compared to normative data andearlier studies in children at comparable ages. Furthermore, the aim was to study if narrative skills correlated with vocabulary, word retrieving and grammatical ability.

The examination was carried out by testing 65 students in the school regarding the chosenlanguage abilities. The results showed that these students had better vocabulary compared to American normative data and earlier Swedish studies. In narratives they produced stories inchronological order and they included a large amount of information. Narrative abilitiescorrelated with receptive vocabulary, word retrieving and grammatical abilities.

It was concluded that reading promoting activities may have affected these student’s languageabilities in a positive way.

I en skola för barn mellan 6 och 9 år i en liten stad i sydöstra Sverige pågår sedan 8 år tillbakaen aktivitet vars ursprungliga syfte var att öka elevernas läsintresse. Alla elever läser minst enbok i veckan och gör därefter en recension som de läser upp i klassen.

Syftet med föreliggande studie var att studera ordförråd, ordmobilisering, narrativ förmågasamt grammatisk förmåga hos eleverna på den utvalda skolan. Frågeställningarna varhuruvida utvalda språkförmågor hos eleverna skiljde sig från normativa data och tidigarestudier av barn i jämförbara åldrar. Vidare undersöktes om narrativ förmåga hade någotsamband med ordförråd, ordmobilisering och grammatisk förmåga.

Undersökningen gjordes genom att 65 elever på skolan testades med avseende på de utvalda språkförmågorna. Resultatet visade att dessa elever hade ett bättre ordförråd jämfört medamerikansk normering och tidigare svenska studier. Gällande elevernas narrativa förmåga berättade de i kronologisk ordning och återgav många delhändelser i historien. Resultatetvisade också att narrativ förmåga hade samband med impressivt ordförråd, ordmobiliseringoch grammatisk förmåga.

Slutsatsen var att den läsfrämjande aktiviteten kan ha påverkat dessa elevers språkförmågorpositivt.

Cette thèse présente une étude de la dynamique des plages sableuses ouvertes dominées par la houle, au travers d’une base de données originale, couvrant une période de 29 mois, et composée de 150 levés DGPS couvrant 750m de linéaire côtier, donnant accès à la morphodynamique du site de Biscarrosse à différentes échelles de temps. Dans un premier temps, l’analyse du jeu de données à l’échelle des événements (tempêtes et successions de tempêtes appelées clusters) nous a permis de montrer que la réponse des plages sableuses aux clusters ne résulte pas de la somme des impacts induits par chaque tempête d’un cluster. Ainsi, l’effet cumulé des clusters, rapporté sur d'autres sites dans la littérature, n’est ici pas vérifié. L'impact de l’enchainement des tempêtes a également été étudié et il en résulte que lors d’un cluster, un changement des conditions hydrodynamique, à savoir, une augmentation des hauteurs de vagues et/ou du niveau d’eau, est nécessaire pour que la tempête suivante ait un impact érosif significatif sur le système. Dans un second temps, nous avons étudié la dynamique saisonnière du système plage/dune, que ce soit la saison hivernale ou estivale, dans le but de mettre en relief les principaux processus impliqués à cette échelle. Nos travaux montrent que la réponse hivernale de la plage ne dépend pas uniquement des conditions énergétiques et du profil pré-hivernal de la plage, mais également du séquençage des événements, comme lors d'un cluster. Mes travaux confirment également la nécessité de prendre en compte de nombreux paramètres dans l’étude de la dynamique hivernale des littoraux sableux : les conditions hydrodynamiques, le séquençage des évènements érosifs mais également reconstructifs, en particulier le ré-engraissement post-évènement, les transports sédimentaires cross-shore et longshore, ainsi que la position de la barre interne et des courants d’arrachements. La saison estivale est, quant-à-elle, marquée par la reconstruction de berme. Elle semble être liée à la fois aux conditions hydrodynamiques et aux caractéristiques des barres sableuses. L’étude de deux étés et deux hivers successifs a ainsi permis d’identifier les interactions entre les saisons et l’impact de la saison hivernale sur l’estivale, et l’influence de la dynamique événementielle sur la dynamique saisonnière. Elle a aussi permis de mettre en relief l’impact de l’urbanisme et des stratégies d’aménagement dans la réponse du système, à différentes échelles de temps
This thesis presents a study of an open sandy beach wave-dominated, based on an original dataset, covering 29 months and composed by 150 DGPS surveys recorded along 750m of sandy shore, giving an access to the morphodynamic of Biscarrosse beach at different timescales. In a first time, event scale analysis showed that sandy beach response to clusters is not the result of the sum of the impact generated by each storm of a cluster on the system. Thus, the cumulated effect of clusters, described in the literature is not verified here. The storm sequencing has also been studied: during a cluster, changes in hydrodynamics conditions (rising of the water level and/or wave height) are necessary to provoke a significant erosion of the system by the second storm. In a second time, we studied the seasonal scale dynamic of the beach/dune system (winter and summer seasons) with the purpose to highlight dominant processes involved at this timescale. Beach response to winter seasons not only depends on hydrodynamic conditions and previous beach profile, but also on erosion/recovery event sequencing, post-storm recovery, cross-shore and longshore sediment transport, the barline characteristics and RIP current positions. Summer seasons are here defined by the berm reconstruction. Recovery periods are both linked to hydrodynamic conditions and barline characteristics (e.g. position and shape).The study of successive winters and summers allowed us to identify interactions between seasons, and the influence of short-scale dynamics on the seasonal one. It also emphasizes the impact of urbanism and coastal management strategies on the system’s response, at different timescales

Frequent-pattern mining from databases has been widely studied and frequently observed. Unfortunately, these algorithms are not suitable for data stream processing. In frequent-pattern mining from data streams, it is important to manage sets of items and also their history. There are several reasons for this; it is not just the history of frequent items, but also the history of potentially frequent sets that can become frequent later. This requires more memory and computational power. This thesis describes two algorithms: Lossy Counting and FP-stream. An effective implementation of these algorithms in C# is an integral part of this thesis. In addition, the two algorithms have been compared.

This Master's thesis deals with the principles of the data mining process, especially with the mining  of association rules. The theoretical apparatus of general description and principles of the data warehouse creation is set. On the basis of this theoretical knowledge, the application for the association rules mining is implemented. The application requires the data in the transactional form or the multidimensional data organized in the Star schema. The implemented algorithms for finding  of the frequent patterns are Apriori and FP-tree. The system allows the variant setting of parameters for mining process. Also, the validation tests and efficiency proofs were accomplished. From the point of view of the association rules searching support, the resultant application is more applicable and robust than the existing compared systems SAS Miner and Oracle Data Miner.

碩士
國立聯合大學
土木與防災工程學系碩士班
105
Taiwan is hit by typhoons every year. The water level will be enhanced as a result of the decreasing the atmospheric pressure during typhoon events. The probability of inundation would be increased and result in property losses of estuaries and coastal nearby residents when the high tide meets the typhoon with strong rainfall. Therefore, the issues of storm surge and river flooding are urgent need to be studied. In the present study, 44 historical typhoons and 360 synthetic typhoons were used to simulate surge heights in Taipei Tamsui River estuary using ADCIRC model. The maximum surge heights were then conducted with frequency analysis to generate surge heights under different return periods in accordance with historical and synthetic typhoons. The combination with surge height and astronomical tide was used to force downstream boundary condition using one-dimensional (1D) unsteady flow model to simulate flooding river stages in Tamsui River watershed. The simulated results reveal that the generated surge heights under 200 and 500 return periods according to historical typhoons will result in overbank flow. The generated surge heights under 100, 200, and 500 return periods based on synthetic typhoons will produce overtopping in river.

In this work we report on experimental insights about random laser emission and propose a novel spectroscopy technique that employs random lasers as the ideal source of illumination. The main part of this work is the demonstration of the first experimental spectral super-resolved reconstruction of a simple transmission function. We show that this can be done using a random laser as light source, taking advantage of its intrinsic stochastic emission properties. In particular, by operating a random laser in its chaotic regime, we obtain an emission spectrum characterized by sharp random spikes, sparsely distributed over the emission bandwidth and which are uncorrelated from shot to shot. These sparse collections of narrow spikes can be used to probe the spectral response of a sample and to reconstruct a high-resolution response function using a ‘bad’, low resolution, spectrometer.

The low latitude tropical ionosphere has been investigated by various researchers using Global Positioning System (GPS). Presently for many civil aviation applications, the ionospheric modeling of the tropical region has gained importance, in particular for flight safety. Since ionosphere is dispersive in nature, dual frequency (L1 = 1575.42 MHz and L2 = 1227.60 MHz) GPS observations can be used to obtain Ionospheric Total Electron Content (TEC). Since TEC varies with local time and geomagnetic latitude, an Ionospheric Modeling Technique using spatial linear approximation of vertical TEC over receiver station has been implemented following Sardon et al. The effects of all the systematic errors due to the satellite plus the receiver (SPR) instrumental biases can reach upto several nanoseconds. (1 TEC is 1016 electrons/m2, 1 ns = 2.86 TEC and 1 TEC = 0.16 m). Hence, to have an accurate estimation of ionospheric TEC, the instrumental biases must also be estimated. This thesis describes a heuristic adaptive Kalman Filtering scheme developed to estimate the TEC, the constants in the linearisation scheme, as well as the above total instrumental biases. The Kalman filter implementation is basically an optimization problem of minimizing the Cost Function J based on the difference between the model output and the measurement, called as the ‘innovation’, scaled by its covariance. In order to obtain the best possible results using the Kalman Filter approach, it is essential to provide appropriate values for the initial state, process and measurement noise covariances (P0, Q and R) respectively, which in general may not be known. Usually manual tuning of the filter parameter is carried out without using the above cost function J! The filter estimates can be highly sensitive to the above chosen statistics and thus these will have to be estimated carefully. Hence, we have utilized the Adaptive Kalman Filtering procedure of Myers and Tapley extended by Gemson and Ananthasayanam. The minimization is carried out by simultaneously estimating the above statistics and the unknown parameters, which include the TEC and the instrumental bias. In addition, A Constant Gain Kalman Filter approach using Genetic Algorithm (GA) has also been developed for the above requirement. It is observed that the steady state gains in KF and AKF approaches are in good match with the constant gains obtained from Genetic Algorithm. Using the above Adaptive Kalman Filtering technique and Constant Gain Kalman Filter approach, vertical TEC values and SPR biases have been estimated from the IGS receiver observations stationed at ISTRAC/ISRO, Bangalore, India. A diurnal TEC variation over Bangalore for a period of one year for 2003 and January 2004 is estimated and reported in this thesis. This approach has also been applied to study the behaviour of the ionosphere over low latitude IGS station at Fortaleza, Brazil data during the great magnetic storm on the 15th July 2000 and the results were found to be consistent with the results of Basu et al. In addition, Using Constant Kalman filter, the TEC enhancement over Indian region has been estimated for the October 2003 Ionospheric storm, and the results were found to be consistent with the reported results in the literature.

Increasing global mean temperature or global warming has the potential to affect the hydrologic cycle. In the 21st century, according to the UN Intergovernmental Panel on Climate Change (IPCC), alterations in the frequency and magnitude of high intensity rainfall events are very likely. Increasing trend of urbanization across the globe is also noticeable, simultaneously. These changes will have a great impact on water infrastructure as well as environment in urban areas. One of the impacts may be the increase in frequency and extent of flooding. India, in the recent years, has witnessed a number of urban floods that have resulted in huge economic losses, an instance being the flooding of Mumbai in July, 2005. To prevent catastrophic damages due to floods, it has become increasingly important to understand the likely changes in extreme rainfall in future, its effect on the urban drainage system, and the measures that can be taken to prevent or reduce the damage due to floods. Reliable estimation of future design rainfall intensity accounting for uncertainties due to climate change is an important research issue. In this context, rainfall intensity-duration-frequency (IDF) relationships are one of the most extensively used hydrologic tools in planning, design and operation of various drainage related infrastructures in urban areas. There is, thus, a need for a study that investigates the potential effects of climate change on IDF relationships. The main aim of the research reported in this thesis is to investigate the effect of climate change on Intensity-Duration-Frequency relationship in an urban area. The rainfall in Bangalore City is used as a case study to demonstrate the applications of the methodologies developed in the research Ahead of studying the future changes, it is essential to investigate the signature of changes in the observed hydrological and climatological data series. Initially, the yearly mean temperature records are studied to find out the signature of global warming. It is observed that the temperature of Bangalore City shows an evidence of warming trend at a statistical confidence level of 99.9 %, and that warming effect is visible in terms of increase of minimum temperature at a rate higher than that of maximum temperature. Interdependence studies between temperature and extreme rainfall reveal that up to a certain range, increase in temperature intensifies short term rainfall intensities at a rate more than the average rainfall. From these two findings, it is clear that short duration rainfall intensities may intensify in the future due to global warming and urban heat island effect. The possible urbanization signatures in the extreme rainfall in terms of intensification in the evening and weekends are also inferred, although inconclusively. The IDF relationships are developed with historical data and changes in the long term daily rainfall extreme characteristics are studied. Multidecedal oscillations in the daily rainfall extreme series are also examined. Further, non-parametric trend analyses of various indices of extreme rainfall are carried out to confirm that there is a trend of increase in extreme rainfall amount and frequency, and therefore it is essential to the study the effects of climate change on the IDF relationships of the Bangalore City. Estimation of future changes in rainfall at hydrological scale generally relies on simulations of future climate provided by Global Climate Models (GCMs). Due to spatial and temporal resolution mismatch, GCM results need to be downscaled to get the information at station scale and at time resolutions necessary in the context of urban flooding. The downscaling of extreme rainfall characteristics in an urban station scale pose the following challenges: (1) downscaling methodology should be efficient enough to simulate rainfall at the tail of rainfall distribution (e.g., annual maximum rainfall), (2) downscaling at hourly or up to a few minutes temporal resolution is required, and (3) various uncertainties such as GCM uncertainties, future scenario uncertainties and uncertainties due to various statistical methodologies need to be addressed. For overcoming the first challenge, a stochastic rainfall generator is developed for spatial downscaling of GCM precipitation flux information to station scale to get the daily annual maximum rainfall series (AMRS). Although Regional Climate Models (RCMs) are meant to simulate precipitation at regional scales, they fail to simulate extreme events accurately. Transfer function based methods and weather typing techniques are also generally inefficient in simulating the extreme events. Due to its stochastic nature, rainfall generator is better suited for extreme event generation. An algorithm for stochastic simulation of rainfall, which simulates both the mean and extreme rainfall satisfactorily, is developed in the thesis and used for future projection of rainfall by perturbing the parameters of the rainfall generator for the future time periods. In this study, instead of using the customary two states (rain/dry) Markov chain, a three state hybrid Markov chain is developed. The three states used in the Markov chain are: dry day, moderate rain day and heavy rain day. The model first decides whether a day is dry or rainy, like the traditional weather generator (WGEN) using two transition probabilities, probabilities of a rain day following a dry day (P01), and a rain day following a rain day (P11). Then, the state of a rain day is further classified as a moderate rain day or a heavy rain day. For this purpose, rainfall above 90th percentile value of the non-zero precipitation distribution is termed as a heavy rain day. The state of a day is assigned based on transition probabilities (probabilities of a rain day following a dry day (P01), and a rain day following a rain day (P11)) and a uniform random number. The rainfall amount is generated by Monte Carlo method for the moderate and heavy rain days separately. Two different gamma distributions are fitted for the moderate and heavy rain days. Segregating the rain days into two different classes improves the process of generation of extreme rainfall. For overcoming the second challenge, i.e. requirement of temporal scales, the daily scale IDF ordinates are disaggregated into hourly and sub-hourly durations. Disaggregating continuous rainfall time series at sub-hourly scale requires continuous rainfall data at a fine scale (15 minute), which is not available for most of the Indian rain gauge stations. Hence, scale invariance properties of extreme rainfall time series over various rainfall durations are investigated through scaling behavior of the non-central moments (NCMs) of generalized extreme value (GEV) distribution. The scale invariance properties of extreme rainfall time series are then used to disaggregate the distributional properties of daily rainfall to hourly and sub-hourly scale. Assuming the scaling relationships as stationary, future sub-hourly and hourly IDF relationships are developed. Uncertainties associated with the climate change impacts arise due to existence of several GCMs developed by different institutes across the globe, climate simulations available for different representative concentration pathway (RCP) scenarios, and the diverse statistical techniques available for downscaling. Downscaled output from a single GCM with a single emission scenario represents only a single trajectory of all possible future climate realizations and cannot be representative of the full extent of climate change. Therefore, a comprehensive assessment of future projections should use the collective information from an ensemble of GCM simulations. In this study, 26 different GCMs and 4 RCP scenarios are taken into account to come up with a range of IDF curves at different future time periods. Reliability ensemble averaging (REA) method is used for obtaining weighted average from the ensemble of projections. Scenario uncertainty is not addressed in this study. Two different downscaling techniques (viz., delta change and stochastic rainfall generator) are used to assess the uncertainty due to downscaling techniques. From the results, it can be concluded that the delta change method under-estimated the extreme rainfall compared to the rainfall generator approach. This study also confirms that the delta change method is not suitable for impact studies related to changes in extreme events, similar to some earlier studies. Thus, mean IDF relationships for three different future extreme events, similar to some earlier studies. Thus, mean IDF relationships for three different future periods and four RCP scenarios are simulated using rainfall generator, scaling GEV method, and REA method. The results suggest that the shorter duration rainfall will invigorate more due to climate change. The change is likely to be in the range of 20% to 80%, in the rainfall intensities across all durations. Finally, future projected rainfall intensities are used to investigate the possible impact of climate change in the existing drainage system of the Challaghatta valley in the Bangalore City by running the Storm Water Management Model (SWMM) for historical period, and the best and the worst case scenario for three future time period of 2021–2050, 2051–2080 and 2071–2100. The results indicate that the existing drainage is inadequate for current condition as well as for future scenarios. The number of nodes flooded will increase as the time period increases, and a huge change in runoff volume is projected. The modifications of the drainage system are suggested by providing storage pond for storing the excess high speed runoff in order to restrict the width of the drain The main research contribution of this thesis thus comes from an analysis of trends of extreme rainfall in an urban area followed by projecting changes in the IDF relationships under climate change scenarios and quantifying uncertainties in the projections.

碩士
銘傳大學
國際企業學系碩士在職專班
97
The density of convenience stores in Taiwan is over those in Japan. Until the October, 2008, the number of convenience store is 9,266. Under such competition environment, it is important to attract customers by using various promotion strategies. For example, some stores use price cut strategy, some use free gift to attract their customers. How is the effect of the promotion frequency on store sales? It needs a further examination. Therefore, the main purpose of this study is to investigate the effects of promotion type, promotion frequency, and promotion occasion on sales of convenience store. Moreover, this study analyzes the intervening effects of business districts, store images, and the customer gender on the relationship between promotion strategies and store sales. In so doing, this study could provide the managerial implications for the convenience stores as well as increase their own competiveness. The study uses secondary data to analyze the study hypotheses. By using stratification sampling method base on 7-11 database, this study found that: (1) Promotion frequency has a significant effect on store sales; (2) The type of business district has a significant effect on store sales; (3) The types of business district has an intervening effect, in other words, business district has significant effect on the relationship between promotion frequency and store sales; (4) Customer gender has an intervening effect, namely, customer gender has a significant effect between promotion frequency and store sales. Therefore, the marketing managers in planning promotion programs should consider factors such as type of business district, loyalty customer, and promotion frequency, etc. Therefore, the individual store could offer his own promotion strategies instead of the promotion strategies provided by the head quarter. Therefore, the individual store could create his maximum sales and profits.

碩士
東吳大學
巨量資料管理學院碩士學位學程
107
In today’s business environment, most of the companies have branches, subsidiaries, chain stores or dealers. And these branches could be located in many different geographical locations. However, the traditional frequent pattern mining algorithm might not be suitable in the multi-store environment nowadays. Therefore, over the last few decades, there have been many studies focus on advanced frequent pattern mining algorithm in a multi-store environment. However, we found that some of the existing methods consider only the multi-store environment problem but might not think about the cloud computing issues, for example, the cost and privacy issues in the cloud computing environment. In contrast, some of them overcome the cloud computing environment issue but not focus on frequent pattern mining in a multi-store environment. In this paper, we propose a new algorithm to remedy this research gap – A Request-Based Frequent Pattern Mining Algorithm (FFPM). We focus on the request-based algorithm and also expect that those frequent patterns under different stores and time periods are considered while considering those cost limitation and privacy problem in the cloud computing environment. To evaluate the efficiency and effectiveness of the proposed method, four experiments are performing in this study. The first experiment is about the running time of FFPM, and the second and third experiments are efficiency and effectiveness of FFPM compared with Apriori algorithm. The last experiment is evaluating FFPM by using a real data set, called SC-POS. Results of this study show that not only on the running time or precision but the proposed method can also find out those frequent patterns under different stores and time periods even more efficiently compared with the traditional frequent pattern mining algorithm.

碩士
國立臺灣海洋大學
商船學系
102
There are so many different kinds of store and spare parts on the ship, which is difficult to do an effective management, and hence a computerized store/spare parts management system is required to let management processes work automatically and efficiently. It is expected to save human resources and reduce mistake. Since RFID has an advantage on breaking space limitations to do checking for tagged item, the RFID is applied in this study to improve the efficiency of management work. We combine the module of RFID and use Web to develop a simplified RFID-type store/spare parts management system. The developed design is helpful in the management process, including the operation of storing and inventorying. After the verification of the actual process, the proposed design is proved to be useful for store/spare parts management process.

碩士
輔仁大學
資訊管理學系碩士班
104
In this study, multi-store and multi-environment support threshold frequent pattern mining, many studies both in the association rule or frequent pattern are faced with the results of exploration accuracy and efficiency. Hu & Chen（2006）proposed CPF-growth algorithm for frequent pattern mining Multiple minimun support, Tang et al.（2008）proposed multi-store environment mining association rules, Both are facing the situation for enterprises to produce. Not a single issue-oriented enterprises are facing a complex problem facing many different configuration. The method proposed in this study will be to obtain more precise information and knowledge in a short time, to meet the needs of different levels of decision-making within the enterprise.

碩士
國立中山大學
企業管理學系研究所
97
From recent year(2008), restaurant, retailing, credit card services industry have began focusing on frequency reward promotion activity to increase business and customers’ loyalty. How do consumers like the activities? Actually, not all customers can be rewarded from their accumulated frequency. Failure of the accumulated frequency to obtain reward may cause consumers negative emotions. And, eventually the bad feeling impacts on their attitude toward the store. The current research developed two types of consumer emotional scale in adjective and in Chinese idioms . Through a 3x2x2 factorial design, 84 participants, 42 students and 42 rank-and -file people, took parts in the experiment, while 3 situations of frequency activities, 2 types of reward, and 2 kinds of business were manipulated, and two categories of criterion measure, emotion and attitude towards store, were implemented. （1）Customers who get reward promotion will have higher positive emotions than who failed to redeem. （2）People with high degree of loss, in the activities have much negative emotions, comparing to these without. （3）Consumer emotions will affect the consumer''s willingness to repeat purchase, likening and emotional attitude towards the store. （4）Different industry will moderate the effect of redemption situations on consumer emotion. （5）The original product type frequency rewards, in certain condition, may solicit more positive emotion than other type of product reward. Keywords: frequency promotion activities, redemption situations in promotion, consumer emotion, measurement for emotion

Nightmares have been described as the most common form of disturbed dreaming. The definition most widely accepted considers two criteria as definitive elements of nightmares, acute anxiety or fear, and awakening from sleep with full alertness. Contemporary studies suggest that nightmares are relatively common and can either be benign or malignant to the point of being compared to psychosis. Thus when nightmares become frequent and/or recurrent, they tend to become problematic and warrant treatment. The current study aimed to investigate the frequency of nightmares in a large community based sample and trial a brief story line alteration technique. More specifically, the current research was designed to conduct two related studies in order to elucidate nightmare frequency and intensity in an Australian sample and examine the efficacy of self-help nightmare treatments. The main hypotheses in the first study predicted that more than 10% of the sample would report weekly nightmares and significant gender differences in reporting nightmares would be observed. Participants in the first study were 440 university students (115 men and 325 women) aged between 18 and 34 (M = 20.41 years). Participants completed the retrospective metric/s Nightmare Frequency Questionnaire (NFQ) and Pittsburgh Sleep Quality Index (PSQI) and Addendum. The results showed that yearly, monthly and weekly nightmares were common, in particular weekly nightmares. However no significant differences between genders were found. Participants in the second study were 20 students who reported weekly nightmares aged between 18-31 (M = 21.6 years) and completed a battery of retrospective metrics including the Nightmare Effects Survey (NES), Posttraumatic Diagnostic Scale (PDS) and the Profile of Mood States (POMS-37 items). The main hypotheses in the second study predicted that the Storyline Alteration Technique (SLAT) would ameliorate nightmare frequency and waking distress overtime and achieve significantly better therapeutic outcomes in contrast to the Systematic Desensitization (SysD) technique. Results showed that the SLAT was efficacious in significantly ameliorating nightmare frequency overtime and in contrast to the SysD technique. It was concluded that weekly nightmares were more prevalent than previous retrospective findings had indicated and self-help nightmare treatments were efficacious in ameliorating nightmare frequency, associated waking distress and poor sleep.

碩士
銘傳大學
管理研究所碩士在職專班
94
In 2003, Taiwan overtook Japan to become the highest distribution density of chained convenience stores in this fierce competitive environment and every chain store systems are brainstorming how to win on the performance. The product of chain store systems is the retail sales and the profit-making source is coming from the sum of each retail store’s achievement. This research is from the point of view of strategic marketing proceeding with the discussion of correlation among the age of stores, frequency of promotions, distribution density of competitors, and governance mechanism of retail sales achievements in the case of Hi-Life convenience store. This research uses Panel data model to analysis and utilizes complete 868 retail sales of Hi-Life convenience stores of the province’s year 2005 sales achievement materials. Found that the age and sales of retail store becomes negative correlation, frequency of promotion and retail sales achievement becomes positive correlation, one competitor appearance and retail sales achievement becomes positive correlation, the appearance of two or more competitors and retail sales achievement becomes negative correlation, last, the governance of alliance and retail sales achievement becomes positive correlation. Headquarters of chain stores shall pay more attention to good joining retail sales and keep good cooperative relationships. As to headquarters of convenience stores, each retails sales is the source of revenue, the competition of each retails sales face shall be taken notice, and the advertising campaign is an essential tool promoting achievement. In the same way, competitors will make their best of this kind of promotional tool. Nonetheless, enterprises must think about how to setup one mechanism to record and dominate every minor environmental change that retail sales might face. How to quick and clear digging out and utilizing those influence parameters is what headquarters shall be continuous working for in the next.